Circuit-interrupting system



Nov. 2 1926.

H. A. TRAVERS ET AL CIRCUIT INTERRUPTING SYSTEM Filed Nov. 13 191 INVENTORS Henry /9. Travers Char/es MaLMaw.

WITNESSES: 0 62. MM

ATTORNEIY Patented Nov. 2, 1926.

UNITED STATES means rATEs'r orrics.

HENRY A. TRAVERS, OF FOREST HILLS BOROUGH, AND CHARLES M012. MOSS,.OF PITTSBURGH, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC & MANU- FAOTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CIRCUIT-INTERRUPTING SYSTEM.

Application filed November 13, 1919. Serial No, 337,635.

Our invention relates to circuit-interrupting systems and particularly to remotelycontrolled systems.

The object of our invention is to prevent an electrically operated circuit interrupter from being held closed when a short circuit or heavy overload obtains thereon.

Electrically operated circuit interrupters are usually closed by an electromagnetic mechanism, such, for example, as a motor or an electromagnet, the moving member of which is operatively connected to the movable member of the circuit interrupter. The circuit interrupter is usually latched in its closed position and, to open the. same, the latch must be released or tripped by means of a trip coil. A remotelydisposed control switch, that is ordinarily manually operated, is used to connectthe coils of the closing or tripping mechanism to a suitable source of electromotive force. If the control switch. is actuated to cause. the circuit interrupter to close while an overload or short circuit obtains on the circuit, overload relays, that are provided for the protection .of the circuit under such conditions, may complete a cir cuit to the trip coil and cause it to release the latch. However, since the coil of the closing mechanism is still energized, through the control switch, the circuit interrupter is held closed through the closing mechanism.

In view of the conditions just stated, we provide a relay switch for automatically opening the circuit that includes the coil or coils of the closing mechanism, after each closing operation of the circuit-interrupter, thus preventing the circuit interrupter from being held closed upon a short circuit or heavy overload if abnormal conditions obtain whenthe control switch is actuated to close the circuit interrupter.

The relay switch is so disposed that the circuit of the coil for energizing the closing mechanism cannot be reestablished until the relay switch has been reset or the control switch moved to its trip position, since, otherwise, the circuit of the closing coil would. be reestablished and the circuit interrupter would close and open again, and would continue this so-called pumping action so long as the control switch should be maintained in its closed position. This continual closing and opening of the circuit interrupter on a heavy overload or short circuitmight damage considerably the apparatus connected to the circuit and subject the circuit-interrupter mechanism toheavy and unnecessary stresses and the contacts to the danger of fusing.

In the accompanying drawings, Figure 1 is a view, partially in diagram and partially in section, of a circuit-interrupting system embodying our invention, and Fig. 2 is a front view of the relay switch shown in Fig. 1. i

A circuit 1. is provided with an interrupter 2 that is adapted to be electrically operated and is controlled by means of a switch 3. A relay switch 4 is adapted to open the circuit that energizes the closing mechanism of the circuit interrupter 2. Overload relays 5, that are operatively connected to the circuit 1, are adapted to cause the circuit interrupter 2 to be tripped when an overload obtains thereon. As shown in Fig. 1, the system may be considered as comprising four separate simple circuits, such as, a closing circuit, a tripping circuit, a lockout circuit and an alarm circuit.

In the closing circuit, the control switch 3, having four stationary contact fingers 6, 7, 8, and 9 and three movable bridging contact members 10, 11 and 12, completes a circuit from a bus-bar 13 through the fingers 7 and 6 and a contact member 10 of the control switch 3, a coil 15 of a relay switch 16, two contact members 17 and 18, and a bridging member therefor, of the relay switch 4 to a bus-bar 19. W hen the switch 16 is thus energized, a circuit is completed from the busbar 19 through the contact members 21 and 22 of the switch 16 and a closing coil 23, of the circuit interrupter 2, to a bus-bar 20.

The closing coil 23, being thus energized,

actuates the closing mechanism 24.

The bus-bar conductors 13 and 14, and 19 and 20 are each supplied with energy from the same source of control energy and illustrate the disposition thereof in a generating station, that is, one circuit .at the control switch 3 and one circuit vnear the interrupter 2.

The tripping circuit is completed by the control switch 3 from the bus-bar 13 through the contact fingers, 7 and 8 and the bridging member 11 of the control switch 3, a trip coil 25, the movable bridging member 26 and the upper stationary contact members 27 of a pallet Switch 29, of the circuit interrupter 2, to the bus-bar 19. Simultaneously, the control switch 3 completes a circuit from the bus-bar 13, through the contact fingers 7, 8, and 9 and the bridging members 11 and 12 of the control switch 3 and a coil 30 of the relay switch 4, to the bus-bar 14. Overload relays 5, that are energied by currents from series current transformers 31, close the contact members 32 thereof, that are connect-ed in parallel relation to the bridging contact member 11 of the control switch 3, to complete a circuit from the bus-bar 13 through the trip coil 25.

The lockout circuit is completed from busbar 20 through a bridging member 33 and upper contact members 27 of the pallet switch 29, a coil 34 and contact members 17 and 18, of the relay switch 4, to the busbar 19,

The alarm circuit is completed from the bus-bar 19 through a movable contact mem- -ber 35 and a stationary contact member 36 of the relay switch 4, the bridging member 33 and the corresponding lower contact members 28 of the pallet switch 29. a bell-alarm bus-bar 37 and a bell 38, to the bus-bar 20.

Lamps 39 and 40, respectively indicate, when either is lighted, whether the main circuit interrupter 2 is open or closed.

When the coil 34 of the relay switch 4 is energized, a plunger 41 is suddenly attracted upwardly thereby, to actuate a pin 42. The sudden movement of the pin 42 forces the heel of a pivoted member 43 upwardly and, simultaneously, compresses a spring 44 under the toe of the member 43. A latching member 45, that is actuated by a compressed spring 46, immediately engages the toe of the pivoted member 43 and latches it in this position, thereby withholding a bridging member 47 from the contact members 17 and 18.

When the coil 30 of the relay switch 4 is energized, the latching member 45 is so attracted thereby as to compress the spring 46 and, simultaneously, to release the toe of the member 43, the spring 44 forcing the heel of the pivot-ed member 43 upward and causing the bridging member 47 to re-bridge the contact members 17 and 18. As the bridging member 47 becomes disengaged from the contact members 17 and 18, the contact member 35 is forced into engagement with the contact member 36 by a spring 48. As the bridging member 47 :e-engages the contact members 17 and 18, the contact members 35 and 36 are disengaged, against the tension of the spring 48. The relation of the contact members 17 and 18, ofvthe relay switch 4, to the closing switch is shown in Fig. 2 of the drawings.

In Fig. 1, the circuit is shown for the open position of the main circuit interrupter 2. In this position, a circuit is completed from the bus-bar 20 through the bridging member 26 and corresponding contact members 28 of the pallet switch 29, the coil 25 of the circuit interrupter 2, and the green lamp 39 to the bus-bar 14. The green lamp 39 indicates, when it is lighted, that the circuitinterrupter 2 is'in its open position.

The red lamp 40 is short-circuited by the trip coil 25 when the interrupter 2 is open and does not, therefore, bccomeincandescent. The trip coil short-circuits either the red lamp 40 or the green lamp 39 depending upon whether the interrupter 2 is open or closed.

To close thecircuit interrupter 2, the control switch 3 is so moved to the right that the bridging contact member 10 engages the contact lingers 6 and 7. The circuit for energizing the switch 16 is completed from the bus-bar 13, through the contact finger 7, the

bridging member 10, and the contact finger 6, of the control switch '3, the coil 15 of the switch 16, the contact member 17, the bridging member 47 and the contact member 18 ofthe relay switch 4, to the bus-bar 19.

The switch 16 is now energized and .a circuit is completed from the bus-bar 19 through the contact members 22 and 21, of the switch 16, and the closing coil 23 vof the circuit interrupter 2, to the bus-bar 20. The closing coil 23, being now energized, actuates the closing mechanism 24 to close the circuit interrupter 2. The closing mechanism 24 also actuates the pallet switch 29, forcing the bridging members 26 and 33 from'engagement with the corresponding lower contact members 28 into engagement with the corresponding upper contact members 27.

A circuit is now completed from the busbar 19 through the bridging member 26 .and the corresponding upper contact members 27 of the pallet switch 29, the trip coil 25 of the circuitinterrupter 2, and the red lamp 4() to the bus-bar 13. The red lamp 40 indicates, when it is lighted, that the circuit interrupter 2 is in its closed position.

A circuit is simultaneously completed from the bus-bar 20 through the bridging member 33 and the corresponding upper contact members 27 of the pallet switch 29 of the circuit interrupter 2, and the coil 34, the contact member 17 the bridging member Y47 and the contact member 18 of the relay switch 4, to the bus-bar 19. The coil 34 of the relay switch 4 being thus energized, attracts the plunger 41 upward. The plunger 41, by virtue of its sudden attraction upward, so imparts a sudden blow to the p n 42 that it suddenly raises the heel of the pivoted member 43 and thereby causes that member to disengage the bridging member 47 from the contact members 17 and 18, and to simultaneously compress the spring 44 under its toe. The pivoted member 45 is immediately forced, by the compression force of the spring 46, to engage and latch the toe of the pivoted member 43, thereby preventing the bridging member 47 from reengaging the cont-act members 17 and 18.

The currents for the coil 15 of the switch 16, and #the coil 34 of the relay switch 4, having both traversed the contact members 17 and 18 and the bridging member 47 of the switch 4, the disengagement of the bridging member 47 opens the respective circuits of the coils 15 and 34 and de-energizes the same.

As soon as the coil 15 of the switch 16 has become de-energized, the circuit through the closing coil 23 of the circuit interrupter 2 is opened at the contact members 21 and 22 of the switch 16 to de-energize the coil 23.

The closing coil 23 thus becomes de-energized immediately after the circuit interrupter 2 is closed, independently of the length of time the control switch 3 is held in closed position after the circuit interrupter 2 has been closed.

If a short-circuit obtains at the time the circuit interrupter 2 is being closed, the overload relays 5 will become energized by the excessive currents from the current transformers 31, and will effect engagement of contact members 32. A circuit will be completed from the bus-bar 13 through the contact members 32 of the overload relays 5, the trip coil 25 of the circuit interrupter 2, the bridging member 26 and the stationary contact members 27 of the pallet switch 29, to the bus-bar 19. The trip coil 25, being thus energized, will actuate the mechanism to trip the circuit interrupter 2.

If the control switch 3 is held in the close position, the circuit interrupter 2 will not close again, since the circuit of the coil 15 of the switch 16 is open circuited between contact members 17 and 18 of the relay switch 4, and, therefore, the circuit of the closing coil. 23 cannot be completed through the contact members 21 and 32 of switch 16 for energizing the closing coil 23 to close the circuit interrupter 2.

In order to close the circuit interrupter 2 again, the control switch 3 must first be moved to the trip position and then back again to the close position.

When the control switch 3 is moved to the left to the trip position, the bridging members 11 and 12 engage the contact fingers 7, 8 and 9, and acircuit is completed from the bus-bar 13, through the bridging members 11 and 12 of the control switch 3, and the coil 30 of the relay switch 4, to the bus-bar 14. The coil 30 of the relay switch 4, being thus energized, actuates the latching member 45, against the compression of the spring 46, to release the pivoted member 43 and permit the bridging member 47 to re-engage the contact members 17 and 18 of the relay switch 4. The closing circuit may now'be completed again and the circuit interrupter 2 reclosed.

If the circuit interrupter 2 has been closed, it is obvious that the relay switch 4 becomes unlatched when the circuit interrupter 2 is tripped again by means of the manually operated control switch 3, but not when the circuit interrupter 2 is automatically tripped by the action of overload relays The bell 38, therefore, is energized, only when the circuit interrupter is tripped automatically, or when a circuit is completed from the bus-bar 20, through the bell 38, the bus-bar 37, the bridging member 33 and the corresponding contact members 28 of the pallet switch 29, and the contact members 36 and 35 of the relay switch 4, to the bus-bar 19. The bell 38 is de-energized when the relay switch 4 is reset.

Although we have shown only one system embodying our invention, we do not wish to be limited thereto, as various modifications may be made in the arrangement of the various elements thereof without departing from the spirit and scope of the invention, as se forth in the appended claims.

We claim as our invention:

1. In a circuit-interrupting system, the combination with an electrically operated circuit-interrupter, means. for closing and means for opening the circuit-interrupter, of means comprising a two-coil relay device for automatically rendering inactive the closing means after each closing of the circuit-interrupter and means cooperating with said twocoil relay device for indicating when the interrupter has been opened by reason of ab normal conditions only.

2. In a circuit-interrupting system, the combination with a circuit-interrupter, adapted to be tripped automatically upon the occurrence of predetermined abnormal conditions, and power-operated means for'closing the circuit-interrupter, of means for admitting energy for operating said power-operated means, means arranged to shut off such supply of energy after the aforesaid means has been in a position to admit energy and after the energy has operated to close the circuit-interrupter, and means associated with said last-mentioned means to indicate only when the circuit-interrupter is tripped automatically.

3. In a circuit-interrupting system, the combination with a circuit interrupter having an auxiliary pallet switch. a closing magnet and a releasing magnet, of means, including a relay switch, for controlling the connection of the closing magnet to a source of current supply, said relay switch having two coils, one coil being adapted to be energized upon the closing of the circuit-interrupter and further adapted to cause the opening of a circuit of the closing magnet, means for latching said relay switch to maintain the circuit open, the other coil of the relay switch being adapted to be energized to unlatch the relay switch, and a manually-operated control switch for controlling the energization of the unlatching coil of the relay switch.

i. In a circuit-interrupting system, the combination with a circuit-interrupter having stationary and movable contact members, an automatic tripping n'iechanism, an auxiliary pallet switch operated by the movable mecnanisi and an electromagnetic device for closing the movable member of the circuit-interrupter, of a relay switch in the circuit of the electron'iagnetic device, means for opening the circuit of the electromagnetic device, said means being actuated with each closing of the circuit-interrupter, and means whereby the electromagnetic device and the tripping mechanisi'n may be actu ated.

5. In an automatic circuit-interrupting system, the combination with main circuit conductors, a circuit interrupter having stationary and movable cont' members, an automatic tripping mechanisn' an auxiliary pallet switch operated by the movable member, and an electromagnetic means for closing the movable member, of a relay switch controlled by the pallet switch for controlling the circuit of the electromagnetic means and adapted to open said circuit each time the circuit interrupter is closed, electro-re sponsive means for automatically causing the release of the circuit interrupter during overload conditions, and a manually-operated control switch electrically connected to the electromagnetic means for controlling the closing and the opening of the circuit interrupter and for causing the relay switch to permit the reestablislnnent of the circuit of the electromagnetic means of the circuit interrupter.

6. In a circuit-interrupting system, the combination with main circuit conductors, and a circuit interrupter having stationary and movable contact members and an automatic releasing mechanism, of electromagnetic means for actuating the movable member of said circuit interrupter, a switch in circuit of the electromagnetic means, and means for effecting the opening of said switch upon the closing of the circuit interrupter and for precluding the reclosing of the interrupter, after an opening thereof by reason of abnormal conditions, until the switch-opening means has been reset.

7. In a circuit-interrupt-ing system, the combination with main circuit conductors, and a circuit interrupter having stationary and movable contact members and an automatic releasing mechanism therefor, oi elec tron'iagnetic means for actuating the movable member of the circuit interrupter, an

auxiliary pallet switch actuated by the movable member of the circuit interrupter, a switch in the circuit of the electromagnetic means, said switch being so connected as to be electrically controlled by the closing of the auxiliary pallet switch when the circuit. interrupter closes.

8. In a circnit-interrupting system, the combination with main circuit conductors, and a circuit interrupter having stationary and movable contact members and an automatic releasing mechanism therefor, of electromagnetic means for actuating the movable member of said circuit interrupter, an auxiliary pallet switch actuated by the movable member of the circuit interrupter, electro-responsive means adapted to energize the releasing mechanism when an overload occurs in the main circuit, a relay switch in the circuit of the electromagnetic means, said switch being adapted to be electrically controlled by the closing of the auxiliary pallet switch when the circuit, interrupter closes.

9. In a circuit-interrupting system, the combination with main circuit conductors, and a circuit-interrupter having stationary and movable contact members and an automatic releasing mechanism therefor, of electromagnetic means for actuating the movable member of the circuit interrupter, an auxiliary pallet switch actuated by the movable member of the circuit interrupter, electro-responsive means adapted to energize the releasing mechanism when an overload occurs in the main circuit, a relay switch in a circuit of the electromagnetic means, a switch therefor electrically controlled by the closing of the auxiliary pallet switch when the circuit interrupter closes, and a manually operated control switch adapted to be electrically connected to cause the actuation of the releasing and the closing mechanism of the circuit interrupter and to eilect the reintroduction of said switch into the circuit of the relay switch.

10. In a circuit-interrupting system, the combination with main-circuit conductors, of a circuit interrupter having a tripping mechanism, a closing magnet coil, an electroi'i'iagnetic switch for completing the circuit through the closing magnet coil to close the circuit interrupter, and an auxiliary pallet switch actuated by the closing mechanism of the circuit interrupter, a relay switch for opening the circuit of the electromagnetic switch when the circuit interrupter is closed, said relay switch being actuated by the completion of a circuit through the pallet switch in the closed position of the circuit interrupter, means for latching the relay switch out of circuit when energized by the circuit completed by the closure of the circuit interrupter, electrore ponsive devices having means to actuate the tripping mechanism of the circuit interrupter, and a manually-operated control switch for completing the circuits of the tripping mechanism and that of the electromagnetic switch and, when moved to the tripping position, to reset said relay switch by releasing the latch mechanism of the relay switch.

11. In a circuitinterrupting system, the combination with main circuit conductors, of a circuit-interrupter having a closing magnet, an automatic tripping mechanism and an auxiliary pallet switch actuated by the circuit interrupter, electro-responsire means for actuating the tripping mechanism of the circuit interrupter upon t-heoccurrence of predetermined overload conditions, a relay switch for controlling the circuit through the closing magnet and so electrically disposed with respect to the auxiliary pallet switch as to be actuated to effect the opening of the circuit of the closing magnet when the circuit interrupter closes, a control switch for controlling the operation of the tripping and the closing mechanisms of the circuit interrupter, and means for resetting the relay switch to permit the reestablishment or" the circuit through the closing magnet.

12. In a circuit interrupting system, the combination with a circuit interrupter, adapted to be tripped upon the occurrence of predetermined abnormal conditions, and powenoperated means for closing the circuit interrupter, of means through which the energy for operating said power-operated means passes, and means arranged to shut off such supply of energy after the other means has been in a position to admit energy to close the circuit interrupter, said latter means serving also to preclude the actuation of the former means to an energy-admitting position until the latter means has been reset and to indicate when the interrupter has been opened by reason of abnormal conditions.

13. In a circuit-interrupting system, the combination with a circuit interrupter adapted to be tripped upon the occurrence of predetermined abnormal conditions, and means for closing the interrupter, 01": means for energizing the closing means, means for rendering the energizing means inactive after each closing of the interrupter and means co-operating with the inactive rendering means for indicating only the tripping of the interrupter because of abnormal conditions.

14. A control circuit for an electricallyoperated circuit interrupter comprising means for closing the interrupter, a switch for controlling the energizing circuit of the closing means, and means for controlling the switch to open the energizing circuit immediately after each closure of the interrupter, for preventing the switch from reestablishing the energizing circuit when'the interrupter is opened by reason of abnormal conditions, and for indicating when the interrupter has been opened by reason of such abnormal conditions.

In testimony whereof, we have hereunto subscribed our names this 1st day of Nov., 1919.

HENRY A. TRAVERS. CHARLES McL. MOSS. 

